impl: check if options are empty (#9617)

googleapis · Aug 2, 2022 · 919c183 · 919c183
1 parent 5d18a03
commit 919c183
Show file tree

Hide file tree

Showing 3 changed files with 15 additions and 0 deletions.
diff --git a/google/cloud/options.cc b/google/cloud/options.cc
@@ -35,6 +35,8 @@ void CheckExpectedOptionsImpl(std::set<std::type_index> const& expected,
   }
 }
 
+bool IsEmpty(Options const& options) { return options.m_.empty(); }
+
 Options MergeOptions(Options preferred, Options alternatives) {
   if (preferred.m_.empty()) return alternatives;
   preferred.m_.insert(std::make_move_iterator(alternatives.m_.begin()),

diff --git a/google/cloud/options.h b/google/cloud/options.h
@@ -33,6 +33,8 @@ namespace internal {
 Options MergeOptions(Options, Options);
 void CheckExpectedOptionsImpl(std::set<std::type_index> const&, Options const&,
                               char const*);
+// TODO(#8800) - Remove when bigtable::Table no longer uses bigtable::DataClient
+bool IsEmpty(Options const&);
 template <typename T>
 inline T const& DefaultValue() {
   static auto const* const kDefaultValue = new T{};
@@ -209,6 +211,7 @@ class Options {
   friend Options internal::MergeOptions(Options, Options);
   friend void internal::CheckExpectedOptionsImpl(
       std::set<std::type_index> const&, Options const&, char const*);
+  friend bool internal::IsEmpty(Options const&);
 
   // The type-erased data holder of all the option values.
   class DataHolder {

diff --git a/google/cloud/options_test.cc b/google/cloud/options_test.cc
@@ -251,6 +251,16 @@ TEST(CheckUnexpectedOptions, OptionsListOneUnexpected) {
               Contains(ContainsRegex("caller: Unexpected option.+FooOption")));
 }
 
+TEST(IsEmpty, Yes) {
+  Options opts;
+  EXPECT_TRUE(internal::IsEmpty(opts));
+}
+
+TEST(IsEmpty, No) {
+  auto opts = Options{}.set<IntOption>(0);
+  EXPECT_FALSE(internal::IsEmpty(opts));
+}
+
 TEST(MergeOptions, Basics) {
   auto a = Options{}.set<StringOption>("from a").set<IntOption>(42);
   auto b = Options{}.set<StringOption>("from b").set<BoolOption>(true);